Eh, I probably should have specified that he was popularly supported before 1813. That business after Leipzig was indeed sketchy, but it appears that the people of Naples preferred him over the Bourbons up until that point.
His landing in Calabria was greatly misjudged, to be sure. Where he was arrested (by the soldiers of Ferdinand IV) was the city of Pizzo, an area that had essentially gotten crushed by the anti-piracy laws passed by Murat. It should be noted that the city of Naples is not in the region of Calabria, but in Campania. He may have met more support had he landed in another area: perhaps Apulia or Abruzzo. We'll never know that though, as he was executed in Pizzo.
The man was a reformer of sorts, but was eventually killed by soldiers of the regime. Historically speaking, southern Italy isn't eager to change, as we see with the Kingdom of Italy (1861-1946). Perhaps it is a response of this kind that resulted in the hostility Murat met at Pizzo, accompanied by exhaustion from approximately twenty years of war and revolution in Italy. All we can do is speculate.
(In all honesty though, landing in such an economically depressed region at the end of a revolutionary era is bad enough. Doing it as the leader who eventually caused this depression, in the holdings of someone such as Ferdinand IV borders on the insane.)
A stunning failure of a return, his reception at Pizzo does not necessarily mean that he was universally disliked. That is like saying a President will go to a town (take my own town, x, for this example) x and meet a terrible reaction there. If this is the case, then the President is widely unpopular. Such logic doesn't add up, of course, so the conclusion needs to be garnered from contemporary writings throughout the Kingdom of Naples.
Brought some somewhat contemporary quotes on Neapolitan government at the time. This is from the Bourbons (to 1799) to the Bourbons (again), and includes the Parthenopean Republic (1799), the Kingdom of Naples (1808-1815) under Murat, and the Kingdom of Naples (1801-1808) under Ferdinand IV.
Spoiler
The Bourbons were unpopular.
"Ferdinand looked askance at our nascent freedom, and from Palermo was trying every means to recover his lost Kingdom. He has powerful allies, who for us were terrible enemies, especially the English..." (Vincenzo Cuoco, Historical Essay on the Neapolitan Revolution of 1799 published 1801)
Neapolitan disregard for the Revolution of 1799 (Naples)
"The immense population of the Capital was more stupefied than active. It was still watching with amazement a change which it had believed almost impossible. In general, it could be said tat the people of the Capital were further from revolution than those in the provinces, since they were less oppressed by taxes and more pampered by a Court which feared them." (Vincenzo Cuoco, Historical Essay on the Neapolitan Revolution of 1799 published 1801)
On Neapolitan Government (1816)
"Its government is an absurd monarchy in the style of Phillip II, which yet manages to preserve a few rags and tatters of administrative discipline, a legacy of the French occupation. It is impossible to imagine any form of government of more abysmal insignificance..." (Stendhal, Rome, Naples, and Florencepublished in 1817.)
NOTE: French occupation=reign of Joachim Murat and the Parthenopean Republic)
Sorry if it's unclear.
